Separation and ink formulation of high purity semiconducting single-walled carbon nanotubes with polymers for printed thin film transistors

In this work, a new approach to sorting SWCNTs based on regioregular poly(3-dodecylthiophene) (rr-P3DDT) has been reported. Effective separation of semiconducting-SWCNTs has been demonstrated by tuning the types of solvent, temperature and centrifugation rate. Figure 1 represents the absorption spectrum of rr-P3DDT sorted CG 200 SWCNTs. TFTs using rr-P3DDT sorted s-SWCNTs as semiconducting ink were fabricated on the SiO2/Si substrate by inkjet printing technique. Charge mobility of 1.2 cm2V-1s-1 and on/off ratio of 2×107 has been achieved as shown in Figure 2 (the ratio of channel width and channel length is 30). Further improvements on the electrical properties of TFTs are underway.